The present invention relates to an exhaust dissipator device, particularly intended for use on rocket motor exhausts, for dissipating the exhaust flow to reduce the thermal and pressure effects on adjacent surfaces.
Rocket exhausts typically comprise a single concentrated supersonic flow which can cause damage to adjacent surfaces as a result of pressure and heating from impingement by the exhaust flow.
Sound suppressing devices for such exhausts have been proposed in the past. For example, in U.S. Pat. No. 2,957,537 of Morgan, a sound suppressor for an aircraft jet engine is shown. The suppressor comprises a series of expansion nozzles for reducing the noise and heat of exhaust gases.
Mufflers or silencers are also shown for use on the exhausts of automobiles and the like. These generally operate by retarding the escape of exhaust gases, but there are problems in ensuring that the retardation does not cause significant back pressure which could affect operation of the motor.
In U.S. Pat. No. 675,830 of Gray, for example, a steam muffler is shown which comprises two concentric cylindrical chambers into which the exhaust projects. Each chamber has a series of openings to allow exhaust gases to escape in various directions, thus retarding the flow and reducing noise.